In a manufacturing process of a semiconductor device in which a laminated structure of an integrated circuit is formed on the surface of, for example, a semiconductor wafer (hereinafter referred to as a “wafer”) as a substrate, a liquid processing step is provided to process the surface of the wafer using a liquid, for example, to remove fine dust or a natural oxide film on the surface of the wafer surface with a cleaning liquid such as, for example, a chemical liquid.
There has been known a supercritical processing method using a fluid in a supercritical or subcritical state (which may also be collectively referred to as a “supercritical fluid”) when removing a liquid or the like attached to the surface of the wafer in the liquid processing process.
When a liquid attached to the surface of the substrate surface is changed to a supercritical fluid or a subcritical fluid, alcohol such as, for example, isopropyl alcohol (IPA) (see, e.g., Japanese Patent Laid-open Publication No. 2013-179245), or hydrofluoroether (HFE) or hydrofluorocarbon (HFC) (see, e.g., Japanese Patent Laid-Open Nos. 2011-187570 and 2014-022566) may be used as a liquid source for the supercritical fluid or the subcritical fluid.